I doubt it’s the firmware. You a’re connected but the Overdrive software isn’t recognizing the unit. I’d try here:
http://help.overdrive.com/customer/portal/articles/1481730-having-trouble-
http://help.overdrive.com/customer/portal/articles/1481660
If you were using Windows and its Overdrive setup, it was probably connecting via MTP–using connections like Windows Media Player. Having switched to Mac, you don’t have Windows Media Player, so the connection is going to be different. Since they make Overdrive for Mac, presumably they have figured this out and have steps to help.
You have the latest firmware. If you want to try updating it, use the manual method.
Basically download from the All Regions link (Version 1 for yours), unzip it, drag it onto the Sansa’s driveletter, disconnect and it will update.
